Pineal gland, ageing, research in US, UK, GDR, Japan

It seems that in the US, UK, Germany, and Japan the thrust of
funding in ageing in mammals is in extrinsic causes (eg RG_Cutler
(1978) "Evolutionary Biology of Senescence" in _Biology of Aging_
edited by JA Behnke (New York, Plenum) pp. 311-60; and D_Harman (1992)
"Free Radical Theory of Aging" _Mutation Research_ 275:257-66) and
dietary restriction (eg EJ_Masoro (1992) "A Dietary Key to Uncovering
Aging Processes" _News in Physiological Sciences_ 7:157-160).
When literature searching I have found conference proceedings
from small groups in Russia and Italy suggesting that pineal
transplant (or even night-time feeding of melatonin) can lead to
increased mean lifespans in rats (eg VA Lesnikov & W Pierpaoli (1994)
"Pineal cross transplantation (Old-to-Yound and vice versa) as
evidence for an Endogenous Aging Clock" Annals NY Acad. Sciences
719:456-460). With the exception of W Regelson (Piepaoli's
collaborator from Richmond, VA) there seems to be no follow up on this
important work, especially curious as there is not (to my knowledge)
any demonstration in mammals that adding oxygen radical scavengers
increases lifespans.
I assume that the lack of follow-up in the US, UK, Germany,
and Japan is due to the skepticism. Has there been any US pursuit of
this idea? Is there evidence for radical scavengers increasing
lifespan in mammals?
Harry Witchel